lemur, generallyStrepsirrhinigenerally, any primitive primate except the tarsier; more specifically, any of the more primitive primates except the tree shrewsindigenous primates of Madagascar. In this the broad sense, the term covers lemur applies not only to the typical lemurs (family Lemuridae) but also to the avahiavahis, sifakas, indri, sifaka, and aye-aye , lorisof Madagascar, in addition to the lorises, potto, and galago (qq.v.). All these animals are characterized by a naked, moist tip to the muzzle; comblike, forward-directed lower front teeth; and a clawlike nail on the second toe of the foot.Typical lemurs are slender primates that are found only on Madagascar and the Comoro Islands. They bush babies of Southeast Asia and Africa. Defined more narrowly, it excludes the last three (the Lorisiformes).

General features

Most lemurs of Madagascar and the nearby Comoros Islands have large eyes, foxlike faces, monkeylike bodies, and long hind limbs. Lemurs range in length (excluding the tail) from about

; the indri, however, has only a stub of a tail. Except for the aye-aye, lemurs have woolly fur that is reddish, gray, brown, or black; some species are variously

marked or striped

patterned with white. Among other markings, they may also have eye-rings or crown patches.

Lemurs are

lower on the evolutionary scale and are

less intelligent than monkeys. Their sense of smell is more acute

,

but

they lack binocular

their vision less so. Although some species are at times active during the day, their eyes seem to be adapted for nocturnal life, trading acuity for increased sensitivity in low light conditions. All lemurs are characterized by a reflective layer (tapetum) behind the retina in the eye, but no fovea or macula lutea; a hairless, moist tip to the muzzle; a noninvasive (epitheliochorial) placenta; comblike forward-directed lower front teeth (with the exception of the aye-aye); and a claw (“toilet claw”) on the second toe of the foot.

Lemurs are docile, gregarious animals

, and

; some species live in groups of 10 or more. Most

are active at night and sleep during the day. Lemurs spend most

of their time is spent in the trees

,

eating

fruits

fruit, leaves, buds, insects, and small birds and birds’ eggs, but diet varies among different species. Some

species are more carnivorous than others. A single young is

, for example, are mainly insectivorous, whereas others feed almost exclusively on foliage. All breed seasonally, and females may have only one fertile day during the entire year. Single offspring are usually born after two to five months’ gestation

, and it

. The newborn lemur then clings to its mother’s underside until it is old enough to ride on her back.

A number of lemurs are rare or endangered. Several either were not discovered until the late 20th century or were rediscovered after having been thought extinct. Remains exist of species larger than any of today’s lemurs. Some of these may have survived until only 500 years ago. They were probably exterminated by overhunting or habitat modification by the Malagasy people, who arrived on the island less than 2,000 years ago.

Lemur diversity

The “true lemurs” (family Lemuridae

includes three

) include five genera and about

nine species, with the typical genus being that of the true lemurs (Lemur)

18 species. The best known of these is the ring-tailed lemur (

L.

Lemur catta),

which

commonly seen in zoos. It is unique both in

both

its habitat (

the

some dry

,

and rocky areas of Madagascar) and

in

for its striped tail

, since

(all other lemurs have solid-coloured tails

. This is the lemur most commonly seen in zoos. Another species of true lemur is the black lemur (L

). Troops are made up of several males and females, and the females are the dominant sex. A male marks the troop’s territory by slashing the trunk of a small tree with a horny spur on his wrist, making an audible click, and leaving a scented scar on the tree. Members of the related genus Eulemur include the black lemur (E. macaco), in which the male is black and the female is reddish brown.

Another genus within the family Lemuridae is that of the nocturnal, bamboo-eating gentle lemurs (Hapalemur). The sportive lemurs make up a separate family (Lepilemuridae), as do the dwarf (Cheirogaleus) and mouse (Microcebus) lemurs, which together make up the family Cheirogaleidae. Mouse and dwarf lemurs are small types that store fat in their rumps and tails and estivate during dry periods.

A number of lemurs are listed in the Red Data Book as rare or endangered animals.

Lemurs first appeared in the Early Eocene Epoch (57.8 to 52

The rare black-and-white or black-and-red ruffed lemurs (genus Varecia) live in rainforests on the eastern side of Madagascar. The gentle lemurs, or lesser bamboo lemurs (genus Hapalemur), and the highly endangered greater bamboo lemurs (Prolemur simus) feed on bamboo stems in the eastern and northwestern rainforests of the island.

There are at least 10 species of sportive lemurs (family Megaladapidae) that live throughout Madagascar in both rainforests and dry forests. They are solitary and nocturnal, feeding on leaves and flowers, which are digested in their enormous cecum with the aid of bacteria. Bacterial fermentation enables energy to be extracted from the large quantity of otherwise indigestible cellulose in the lemur’s diet.

The dwarf lemurs (Cheirogaleus), along with the mouse (Microcebus), Coquerel’s (Mirza), hairy-eared (Allocebus), and fork-crowned (Phaner) lemurs, make up the family Cheirogaleidae, which in many respects are the most primitive living lemurs. Dwarf lemurs store fat in their tails and are dormant (estivate) during dry periods; they live in monogamous pairs. Mouse lemurs, which eat insects and fruit, are the smallest living primates.

Strepsirrhine primates first emerged in the Early Eocene Epoch (some 50 million years ago), though their origins may be traced to the preceding Paleocene Epoch. These

early

Eocene lemuroids were

moderately

abundant

and are found as fossils

in

deposits in

North America and Europe

. One Eocene form, Notharctus (q.v.), is particularly well-

, and some are known from complete

fossil remains

skeletons.

At

By the close of the Eocene (

36.6

approximately 34 million years ago),

Notharctus and related forms

strepsirrhines had practically disappeared from the Northern Hemisphere. The

lemurs

lemur lineage continued in tropical forests, however, and they were particularly successful in Madagascar, where they were relatively free from competition with more-advanced primates. No fossil deposits are known in Madagascar between the Mesozoic Era and recent times, so the fossil history of the island’s lemurs is unknown.

Russel A. Mittermeier, Lemurs of Madagascar (1994), is a field guide including maps and 36 colour plates; Spirits of the Forest (1987), produced by WNET as part of the Nature television series, portrays several species and behaviours.